1. Field of the Invention
The present invention generally relates to a liquid crystal display device. More specifically, the present invention relates to a liquid crystal display device having a flexible printed cable.
2. Background Information
As shown in FIGS. 6 to 8, a conventional liquid crystal display device includes a frame 101, a liquid crystal cell 102, a light guide plate 103, a metal bezel 105, a polarizing plate 115, a prism sheet 116, a diffusion sheet 117 and a reinforcing plate 118. The frame 101 is made of a synthetic resin and is open at a front face. The frame 101 includes a base plate 101a and upper, lower, left, and right side plates 101b to 101e protruding integrally from outer peripheral edges of the base plate 101a. A liquid crystal cell 102 and a light guide plate 103 are disposed within the frame 101. The light guide plate 103 is made of an acrylic resin or other such translucent resin. Light emitting diodes (LEDs) are disposed in a gap 104 formed between the light guide plate 103 and the lower side plate 101c of the frame 101. Latching tabs 106 protrude integrally from outer peripheral faces of the side plates 101b to 101e. The latching tabs 106 are engaged in latching holes 105a formed in the side plates of the metal bezel 105. The metal bezel 105 is removably fitted to the frame 101 in a state of holding down outer peripheral edge of the liquid crystal cell 102.
A cell drive-use lead wire 107 and a lighting-use lead wire 108 are extended to outside the frame 101. The cell drive-use lead wire 107 includes a flexible printed cable electrically coupled to the liquid crystal cell 102. The lighting-use lead wire 108 includes a flexible printed cable electrically coupled to the LEDs. Furthermore, one end of the lighting-use lead wire 108 is electrically coupled to the cell drive-use lead wire 107.
As shown in FIGS. 8A and 8B, the lighting-use lead wire 108 is formed in a T shape by a lead wire main body 108a and an extension wire 108b. The lead wire main body 108a is for mounting the LEDs. The extension wire 108b protrudes integrally from the lead wire main body 108a. The lead wire main body 108a and the extension wire 108b include a printed circuit 111 and two insulating films 109 and 110 formed on both sides of the printed circuit 111. One insulating film 109 is partially removed to expose lands 111a of the printed circuit 111 in a middle portion and at both ends of the lead wire main body 108a. The LEDs are attached with solder S to the lands 111a. The other insulating film 110 is also partially removed to expose lands 111b of the printed circuit 111 at the end of the extension wire 108b. 
As shown in FIG. 7, the LEDs are affixed to a rear face of the liquid crystal cell 102 by a double-sided adhesive 113 via the lead wire main body 108a and a light blocking tape 112 in order to fix the LEDs at proper locations within the gap 104.
As shown in FIG. 7, the cell drive-use lead wire 107 has the same structure as the lighting-use lead wire 108. The lands 111b of the extension wire 108b are connected to the lands 111c of the printed circuit 111, which are exposed by partially removing the insulating film 109 of the cell drive-use lead wire 107. The reinforcing plate 118 is made of a synthetic resin and fastened to the end of the cell drive-use lead wire 107.
The cell drive-use lead wire 107 is connected to a drive circuit via a connector 114 to emit light from the LEDs. The emitted light goes through the light guide plate 103 and illuminates the liquid crystal cell 102 from behind. Japanese Laid-Open Patent Application No. 2005-173302 discloses a liquid crystal display device having a similar structure.
With the conventional liquid crystal display device, not only the insulating film 109 formed on one side of the printed circuit 111, but also the insulating film 110 formed on the other side of the printed circuit 111 has to be partially removed to expose the lands 111a and 111b. Thus, the number of process to produce the conventional liquid crystal display device is increased, which correspondingly increase the production expense.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved liquid crystal display device. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.